.\" Copyright (C) 2005 Robert Love
.\" and Copyright (C) 2008, Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" SPDX-License-Identifier: GPL-2.0-or-later
.\"
.\" 2005-07-19 Robert Love <rlove@rlove.org> - initial version
.\" 2006-02-07 mtk, minor changes
.\" 2008-10-10 mtk: add description of inotify_init1()
.\"
.TH inotify_init 2 2022-12-04 "Linux man-pages 6.03"
.SH NAME
inotify_init, inotify_init1 \- initialize an inotify instance
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <sys/inotify.h>
.PP
.B "int inotify_init(void);"
.BI "int inotify_init1(int " flags );
.fi
.SH DESCRIPTION
For an overview of the inotify API, see
.BR inotify (7).
.PP
.BR inotify_init ()
initializes a new inotify instance and returns a file descriptor associated
with a new inotify event queue.
.PP
If
.I flags
is 0, then
.BR inotify_init1 ()
is the same as
.BR inotify_init ().
The following values can be bitwise ORed in
.I flags
to obtain different behavior:
.TP
.B IN_NONBLOCK
Set the
.B O_NONBLOCK
file status flag on the open file description (see
.BR open (2))
referred to by the new file descriptor.
Using this flag saves extra calls to
.BR fcntl (2)
to achieve the same result.
.TP
.B IN_CLOEXEC
Set the close-on-exec
.RB ( FD_CLOEXEC )
flag on the new file descriptor.
See the description of the
.B O_CLOEXEC
flag in
.BR open (2)
for reasons why this may be useful.
.SH RETURN VALUE
On success, these system calls return a new file descriptor.
On error, \-1 is returned, and
.I errno
is set to indicate the error.
.SH ERRORS
.TP
.B EINVAL
.RB ( inotify_init1 ())
An invalid value was specified in
.IR flags .
.TP
.B EMFILE
The user limit on the total number of inotify instances has been reached.
.TP
.B EMFILE
The per-process limit on the number of open file descriptors has been reached.
.TP
.B ENFILE
The system-wide limit on the total number of open files has been reached.
.TP
.B ENOMEM
Insufficient kernel memory is available.
.SH VERSIONS
.BR inotify_init ()
first appeared in Linux 2.6.13;
library support was added in glibc 2.4.
.BR inotify_init1 ()
was added in Linux 2.6.27;
library support was added in glibc 2.9.
.SH STANDARDS
These system calls are Linux-specific.
.SH SEE ALSO
.BR inotify_add_watch (2),
.BR inotify_rm_watch (2),
.BR inotify (7)
